The iPhone now accounts for 40% of AdMob's mobile network usage, gaining ground against Nokia's Symbian (which fell to 34%), and staying way ahead of any other platform (RIM was third, falling from 10% to 8%).

Clearly, that's HUGE. However, it's important to remember exactly what these measures are, however, and are not. A reminder from AdMob:

AdMob Mobile Metrics report is a reflection of the data flowing through our network each month. The statistics do not represent handset sales or unique devices in the market, rather they represent the relative mobile usage we see from the sites and apps in our network.

We won't let that stop us from asking Microsoft CEO, Steve Ballmer -- who recently told TechCrunch that Safari's desktop marketshare a "rounding error", what that makes Windows Mobile's 4% share?